1. Field of the Invention
The present invention relates to a buckle device that structures a vehicle seat belt device and holds a tongue plate attached to webbing.
2. Description of the Related Art
Buckle devices currently known include, for example, a buckle device provided with a lock plate that is rotatably supported at the device body and that holds a tongue plate at the device body by approaching and engaging with a tongue plate inserted into the device body, and a lock member that engages with the lock plate in the above-described state of engagement and prevents separation of the lock plate from the tongue plate (see, for example, Japanese Patent Application Laid-Open (JP-A) No. 2003-125811).
In this kind of buckle device, when a release button mounted at the device body is operated by pressing, the lock member oscillates, allowing the separation of the lock plate from the tongue plate, and the holding of the tongue plate is thus released.
Incidentally, in buckle devices similar to that described above, the lock member is manufactured by fixing together with rivets two parts (a body portion and a counter-mass) formed by press working, and by having the lock member supported at the device body by a spindle part that is formed to project from one press worked part (the body portion), the lock member can oscillate around the spindle part. Further, in this kind of lock member, the two press worked parts are provided with a specified weight so as to achieve the so-called “counter effect”.
However, while there is a demand for miniaturization of buckle devices, limitations to the width dimensions of the lock member have made it difficult to secure the weight of the lock member.